Investigation and Mitigation of Power Quality problems using Dynamic Voltage Restorer with Super Capacitor based Energy Storage (Case study St. George Brewery, BGI Ethiopia)

Abstract

Electricity is an easy source of energy that has become more and more important with the development of technology. However, various conditions of the power system can affect the quality of the electricity, leading to power quality issues that can reduce the efficiency of the system. Nowadays, power quality has grown to be a serious issue. in modern power systems due to the increasing use of sensitive loads. Many industries in our country are facing issues with power quality, which has various causes. This thesis presents a comprehensive investigation of power quality problems in St. George Brewery and proposes a Dynamic Voltage Restorer (DVR) with a Super Capacitor based Energy Storage system as a solution. The proposed system was designed and simulated using MATLAB SIMULINK. The research work begins with a detailed analysis of power quality problems and their impact on electrical systems. The necessary information for the study is gathered by using a Fluke 435 Power Quality and energy Analyzer as well as recorded data. The measurements have been collected, and it has been recorded that the voltage sags are below 65% of the root-mean-square voltage and the total harmonic distortion of current (THD) value reaches 25.07%. After collecting the data, an analysis has been conducted, comparison with IEEE standards and computer simulations have been executed using the MATLAB/Simulink model to exemplify the effectiveness of the mitigation methods. The proposed DVR system is then introduced, including a discussion of its operation, design considerations, and control techniques. The integration of super capacitors as the energy storage in the DVR system is also analyzed. Furthermore, single tuned multi-branch passive filters have been developed and simulated for the reduction of harmonics distortion. The filters were successful in attenuating the harmonics, which ultimately led to a decrease in the total harmonics distortion value from 25.07% to 2.89%. The results demonstrate that the proposed DVR system with super capacitor-based energy storage provides an effective solution for mitigating power quality problems and improving the overall quality of power supply.